Female sex reduces the risk of hospital-associated acute kidney injury: a meta-analysis

Abstract

Background: Female sex has been included as a risk factor in models developed to predict the development of AKI. In addition, the commentary to the Kidney Disease Improving Global Outcomes Clinical Practice Guideline for AKI concludes that female sex is a risk factor for hospital-acquired AKI. In contrast, a protective effect of female sex has been demonstrated in animal models of ischemic AKI.

Methods: To further explore this issue, we performed a meta-analysis of AKI studies published between January, 1978 and April, 2018 and identified 83 studies reporting sex-stratified data on the incidence of hospital-associated AKI among nearly 240,000,000 patients.

Results: Twenty-eight studies (6,758,124 patients) utilized multivariate analysis to assess risk factors for hospital-associated AKI and provided sex-stratified ORs. Meta-analysis of this cohort showed that the risk of developing hospital-associated AKI was significantly greater in men than in women (OR 1.23 (1.11,1.36). Since AKI is not a single disease but instead represents a heterogeneous group of disorders characterized by an acute reduction in renal function, we performed subgroup meta-analyses. The association of male sex with AKI was strongest among studies of patients who underwent non-cardiac surgery. Male sex was also associated with AKI in studies which included unselected hospitalized patients and in studies of critically ill patients who received care in an intensive care unit. In contrast, cardiac surgery-associated AKI and radiocontrast-induced AKI showed no sexual dimorphism.

Conclusions: Our meta-analysis contradicts the established belief that female sex confers a greater risk of AKI and instead suggests a protective role.

Keywords: Acute kidney injury; Acute renal failure; Gender; Meta-analysis; Systematic review.

Fig. 1

Flow diagram describing the identification of studies included in the meta-analysis

Fig. 2

Meta-analysis of 28 studies that provided adjusted sex-stratified data regarding the incidence of hospital-associated AKI

Fig. 3

Subgroup meta-analysis of 68 studies that provided unadjusted sex-stratified data regarding the incidence of hospital-associated AKI. Abbreviations used: ICU Intensive care unit; HA Hospital-associated AK; CSAKI Cardiac surgery-associated AKI

Fig. 4

Funnel plot of studies that analyzed risk factors for hospital-associated AKI and provided sex-stratified odds ratios